Improvement in piston-packings



`the plane of section.

ADAM s. cAMEEoN, oE NEW Yonx, N. Y.

`IMPRQVEMEN'IV IN PISTON-PACKINGS.

Specification formingpartof Letters Patent No. 112,685, dated March 14, 1871.

To altwhom it 'may concern: Y r

Be it known that I, ADAM S. CAMERON, of the city, county, and' State of New York,

p have invented a new and Improved Fiston- Packing; and I do hereby declare the 'following to be a full, clear, and exact descrip- 'tion thereof, which will enable those skilled in the art to make and use the same, reference being had to the accompanying drawing, forrn ing part of this specification, in which draw.-

lng- .i

Figure l represents a side View of this invention. Fig.- 2 is a longitudinal central section ofthe same. Fig.'3 is aptransverse section of the same, the line mx,Fi g. 2, indicating Similar letters indicate corresponding parts.

This invention relates to a piston-packing' which is composed of two screw-wedges which are tapped to t on a screw-thread cut on the pistonrod, and the inner 'conical surfaces of which act on corresponding surfaces of split rin gs, so that by screwing u p said screw-wed ges the split rings are expanded. From the inner ends of the screw-wedgesextend suitable projections, of such a length that when the split rings are expanded exactly to thexdesired de `gree said projections bear againsteach other,

\ and as the split rings wear away the projecf tions are gradually tiled ofi'. so that the packing can always] be kept tight without crowding toohard against the inner surface of the cylinder. The outer edges ofthe split rings project beyond the screw-wed ges, so as to form bearing-surfaces for the fluid acting on or being acted on by the piston, and to enable said iiuid to assist in keeping the split rings expanded sufficiently to prevent leakage past i the piston. i

`In the drawing, the letter A designates a piston, the body ofwhich` is composed of two cones or wedges, c`t"(t, `bored out and tapped so as to t on a screw-thread, b, cuton the piston-rodl? the conical surfaces of said screw-` wedges being so arranged thatthey face each other, as shown in Fig. 2. i

The packing consists of two split rings, c c', the inner edges of which are turned off square, `while their edges are turned out conical to correspond tothe cone-surfac`es of the screw wedges. By screwing up the screw-wedges, therefore, the split rings are expanded and caused to bear tight against the inner surface of the cylinder C.

Suitable square or hexagonal shoulders d d on the outer surfaces of the screw wedges give a chance to apply a screwwvrench for the purpose of turning said screw-wedges in or out.

From the inner surfaces of the screw-wed ges extend projections e e', the length of which is so regulated that they bear against each other when the split rings are expanded just far enough to fit close against the inner surface of the cylinder. If either the split rings or the inner surface of the cylinder wear o", the projections e e', or either of them, is filed oft' a little, to allow the screw-wedges to close up and to expand the split rings sufficiently to compensate for the wear. Y'

The outer edges of the split rings project beyond the edges of the screw-wedges, so as to'forln annular bearing-surfaces ff', and to enable the iuld acting on or being acted on by the piston to assist in expanding the split rings sufficiently to prevent leakage past the piston.

If the split rings are made without these annular bearing-surfaces, the fluid is liable to pass in between the outer surfaces of the split rings and the inner surface of the cylinder, thus acting so as to compress said split rings, whereby the piston becomes leaky and its useful effect is partially destroyed.

My4 packing is intended particularly for small pistons, and it can be used with advantage for packing pistons of pumps or steam cylinders. i

What I claim as new, and desire to secure by Letters Patent, is

The screw-wedges a c', iitted to screw on the.

y A. S. CAMERON.

Witnesses: Y

\ W. HAUFF,

C. WAHLERS.- 

